This invention relates to vehicle parking brake mechanisms and, more particularly, to parking brake mechanisms of the character wherein a foot pedal lever is depressed to tension a brake cable by which the parking brake is set.
It is of course well known to provide a vehicle with a parking brake mechanism of the character including a foot operated pedal lever which is displaced from a retracted to a depressed position to achieve tensioning of the brake cable and setting of the parking brake. In certain of such mechanisms heretofore provided, the brake cable is directly attached to the pedal lever and the pedal lever is releaseably retained in the depressed position in which the parking brake is set and, thus, against the tension in the brake cable. Upon release of the parking brake mechanism, the foot pedal lever is returned to its retracted position with tremendous force as a result of the cable tension. Such brake mechanisms include a pedal lever bumper or stop to arrest the pedal lever in the retracted position, and the return force of the pedal lever results in rapid deterioration of the bumper and a loud noise upon impact between the pedal lever and bumper. Moreover, an undesirably heavy construction of the component parts is required to prevent a change in the retracted position of the pedal lever due to pedal lever or bumper deflection resulting from repeated high force impacting therebetween. Other attempts to dampen the high force return of brake pedal levers which are set under cable tension, such as through the use of dampening springs and air springs, are unacceptable from the standpoint of high cost and, moreover, such devices create problems with respect to assuring repeated return of the pedal lever completely to its retracted position while keeping the necessary pedal actuating force below the government standard of one-hundred and twenty-five pounds.
Efforts to avoid the foregoing disadvantages of cable returned pedal levers have included multi-stroke type brake mechanisms. In mechanisms of the latter character, the pedal lever is stroked one or more times to the depressed position to rotate a cable actuator which tensions the brake cable and holds the latter in its tensioned position, and the brake lever returns to its retracted position after each stroke and thus is in its retracted position when the parking brake is actuated. Brake mechanisms of this character, however, are objectionable to vehicle operators in that there is no visual indication as to whether or not the parking brake is set. This can result in mental anguish and/or undesirable wear or damage to the brake mechanism when, for example, the operator attempts to drive the vehicle when the parking brake is set. Such anguish and possible physical injury can occur when, as another example, the operator wants the brake set and, thinking that it isn't, pushes the brake pedal expecting resistance and there is none. In the latter situation, the operator could check as to whether the brake is set or not by pulling on the mechanical release mechanism, but doing so would of course release the parking brake requiring the operator to reset it, whereby the frustration is not avoided.